Red List habitat classification > RLD - Mires and bogs > RLD4.1b Tall-sedge base-rich fen

Tall-sedge base-rich fen

Quick facts

Red List habitat type code RLD4.1b
Threat status
Europe Endangered
EU Endangered
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)

Summary

Tall-sedge base-rich fens are dominated by the tall to medium-tall graminoids Cladium mariscus, Juncus subnodulosus, Schoenus ferrugineus (in subcontinental areas) and S. nigricans (in Atlantic and Mediterranean areas). In some stands also Phragmites australis occurs, but it does not form dense stands. Small sedges and short-growing herbs also occur in places, but their number and abundance are smaller here than in small-sedge fens. Stands with Cladium mariscus can be very dense and species-poor.

These fens typically occur on flat landforms in lowlands and submontane areas near springs with base-rich water, especially where the bedrock is formed of limestone, chalk or marl. They are generally wetter than the other types of base-rich fens and their water table is high also in summer. In places, long-term inundation of the soil surface can result in the occurrence of muddy patches with sparse vegetation after draw-down, which are microhabitats of Drosera anglica and the moss Scorpidium scorpioides.

Tall-sedge base-rich fens occur across the entire European continent, but they are considerably more common in the Atlantic and boreal regions and in the lowland areas of Central Europe, where they are the main type of base-rich fens.

Based on the palaeoecological evidence, tall-sedge base-rich fens were more common in the Late Pleistocene and early Holocene than today in non-glaciated parts of Europe, but they changed into Sphagnum fens after landscape acidification or retreated as a result of terrestrialisation of wetlands in the course of natural succession. In the last two centuries many of these fens have been destroyed due to artificial drainage. Some of these fens are grazed or occasionally cut, but at many sites their vegetation is natural and does not depend on management.

Indicators of good quality:

  • Stable hydrological regime
  • Absence of overgrazing
  • No encroachment of trees or shrubs
  • No spread of meadow or reed species

Characteristic species
For full habitat description, please download the habitat factsheet.

Threat status

Synthesis of Red List assessment

The resulting category Endangered (EN) is indicated by recent area loss (A1) after data simulation (described in the assessment) which gives a realistic loss of more than 50% at the European scale. The threshold for EN category was however exceeded only slightly, and other categories suggest rather the VU or NT category. Obviously, tall-sedge fens are somewhat less threatened than D4.1a Short-sedge fens and the VU category would mirror this difference. On the other hand, placing them into the same EN category makes sense, considering still continuing habitat deterioration, especially in agricultural landscapes of Central, Western and Southern Europe.
EU
Red List Category Red List Criteria
Endangered A1
Europe
Red List Category Red List Criteria
Endangered A1

Confidence in the assessment

medium
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Agriculture
    • Modification of cultivation practices
    • Agricultural intensification
    • Grassland removal for arable land
    • Mowing / Cutting of grassland
    • Abandonment / Lack of  mowing
    • Grazing
    • Intensive grazing
    • Intensive cattle grazing
    • Abandonment of pastoral systems, lack of grazing
  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Diffuse pollution to surface waters due to agricultural and forestry activities
    • Diffuse pollution to surface waters due to transport and infrastructure without connection to canalization/sweepers
    • Soil pollution and solid waste (excluding discharges)
    • Other forms of pollution
  • Natural System modifications
    • Human induced changes in hydraulic conditions
    • Landfill, land reclamation and drying out, general
    • Reclamation of land from sea, estuary or marsh
    • Canalisation & water deviation
    • Modification of hydrographic functioning, general
    • Water abstractions from groundwater
    • Management of aquatic and bank vegetation for drainage purpose
    • Other ecosystem modifications
    • Anthropogenic reduction of habitat connectivity
  • Natural biotic and abiotic processes (without catastrophes)
    • Biocenotic evolution, succession
    • Species composition change (succession)
  • Climate change
    • Changes in abiotic conditions
    • Droughts and less precipitations

Habitat restoration potential

Naturally only if habitat specialists have survived at the site, nutrient availability is not increased and the water regime is unaffected.
Through intervention restoration is extremely difficult as demonstrated by several studies, especially because of problems with nutrient oversupply and iron toxicity.

Trends in extent

Average current trend in quantity

Decreasing Decreasing
EU28 EU28+

Trends in quality

Average current trend in quality

Decreasing Decreasing
EU28 EU28+

Conservation and management needs

Desirable conservation measures include:
No intervention - in well waterlogged, nutrient-poor fens, especially in high-boreal and some mountain regions.
Mowing - in fens enriched in nutrients or with a lowered water level, in fens invaded by Phragmites, Calamagrostis, Filipendula or tall sedges and willows.
Artificial disturbances - if acidicole, late-successional Sphagnum species invade, disturbances without nutrient input (e.g., removal of expanding peatmosses) may be applied to support original brown-moss vegetation.
Creating buffer zones filtering nutrients and hydrological buffer zones.
Extensive restoration measures (blocking drainage channels, sod removal, planting Pedicularis palustris as a hemiparasite to supress reed and tall sedges) in heavily damaged fens.

List of conservation and management needs

  • No measures
    • No measures needed for the conservation of the habitat/species
  • Measures related to agriculture and open habitats
    • Maintaining grasslands and other open habitats
  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
    • Restoring/Improving the hydrological regime
    • Managing water abstraction
  • Measures related to spatial planning
    • Establish protected areas/sites
    • Legal protection of habitats and species
    • Manage landscape features
  • Measures related to urban areas, industry, energy and transport
    • Urban and industrial waste management

Distribution

For each habitat a distribution map was produced from a wide variety of sources indicating known and potential occurrences of the habitat in 10x10 km grids within Europe. Occurrences in grid cells were given in two classes: actual distribution from relatively reliable sources (surveys, expert knowledge), and potential distribution based on models or less reliable indicators. Please download the fact sheet to see the map.

Geographic occurrence and trends

EU28 Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)
Austria Present 3.9 Decreasing Decreasing
Belgium Present 0.1 - -
Bulgaria Present 0.01 Decreasing Decreasing
Croatia Present Unknown - -
Czech Republic Present 0.6 Decreasing Decreasing
Denmark Present Unknown - -
Estonia Present 55 - Unknown
Finland mainland Present 0.05 Unknown Decreasing
France mainland Present 125 Decreasing Decreasing
Germany Present 10 Decreasing Decreasing
Crete Present 0.1 - -
Hungary Present 8.5 Decreasing Unknown
Ireland Present 90 Decreasing Decreasing
Italy mainland Present 13 Decreasing Decreasing
Latvia Present 2.2 Decreasing Decreasing
Lithuania Present 1 Decreasing Decreasing
Netherlands Present - Decreasing
Poland Present 45 Decreasing Decreasing
Romania Present 10 Decreasing Decreasing
Slovakia Present 10 Decreasing Decreasing
Slovenia Present 1 Decreasing Decreasing
Spain mainland Present 33 Decreasing Decreasing
United Kingdom Present 4.2 Decreasing Decreasing
Sweden Present 75 Unknown Decreasing
EU28 + Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)
Albania Present 3 Decreasing Decreasing
Bosnia and Herzegovina Present 15 Decreasing Decreasing
Former Yugoslavian Republic of Macedonia (FYROM) Present Unknown Unknown Decreasing
Switzerland Present 30 Decreasing Decreasing
Norway Mainland Present 10 - Decreasing

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 7465150 2054 488
EU28+ 2254 536
AOO = the area occupied by a habitat measured in number of 10x10 km grid cells.
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).

Characteristic species

The full list of characteristic species and genus are available above from the Summary. The species available in the EUNIS database are shown here.
Flowering Plants Carex davalliana
Flowering Plants Carex lasiocarpa
Flowering Plants Cladium mariscus
Flowering Plants Drosera anglica
Flowering Plants Epipactis palustris
Flowering Plants Eriophorum angustifolium
Flowering Plants Eriophorum latifolium
Flowering Plants Eupatorium cannabinum
Flowering Plants Hydrocotyle vulgaris
Flowering Plants Juncus subnodulosus
Flowering Plants Lythrum salicaria
Flowering Plants Mentha aquatica
Flowering Plants Menyanthes trifoliata
Flowering Plants Molinia caerulea
Flowering Plants Parnassia palustris
Flowering Plants Phragmites australis
Flowering Plants Salix cinerea
Flowering Plants Salix repens
Flowering Plants Schoenus ferrugineus
Flowering Plants Schoenus nigricans
Mosses & Liverworts Bryum pseudotriquetrum
Mosses & Liverworts Palustriella commutata
Mosses & Liverworts Plagiomnium affine
Mosses & Liverworts Scorpidium scorpioides
Species scientific name English common name Species group
Carex davalliana Flowering Plants
Carex lasiocarpa Flowering Plants
Cladium mariscus Flowering Plants
Drosera anglica Flowering Plants
Epipactis palustris Flowering Plants
Eriophorum angustifolium Flowering Plants
Eriophorum latifolium Flowering Plants
Eupatorium cannabinum Flowering Plants
Hydrocotyle vulgaris Flowering Plants
Juncus subnodulosus Flowering Plants
Lythrum salicaria Flowering Plants
Mentha aquatica Flowering Plants
Menyanthes trifoliata Flowering Plants
Molinia caerulea Flowering Plants
Parnassia palustris Flowering Plants
Phragmites australis Flowering Plants
Salix cinerea Flowering Plants
Salix repens Flowering Plants
Schoenus ferrugineus Flowering Plants
Schoenus nigricans Flowering Plants
Bryum pseudotriquetrum Mosses & Liverworts
Palustriella commutata Mosses & Liverworts
Plagiomnium affine Mosses & Liverworts
Scorpidium scorpioides Mosses & Liverworts

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

This habitat may be equivalent to, or broather than, or narrower than the habitats or ecosystems in the following typologies.
Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 200711 D4.1 Rich fens, including eutrophic tall-herb fens and calcareous flushes and soaks narrower
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